Power DAC. WM8918 Datasheet

WM8918 DAC. Datasheet pdf. Equivalent

WM8918 Datasheet
Recommendation WM8918 Datasheet
Part WM8918
Description Ultra Low Power DAC
Feature WM8918; w WM8918 Ultra Low Power DAC for Portable Audio Applications DESCRIPTION The WM8918 is a high per.
Manufacture Wolfson Microelectronics
Datasheet
Download WM8918 Datasheet




Wolfson Microelectronics WM8918
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WM8918
Ultra Low Power DAC for Portable Audio Applications
DESCRIPTION
The WM8918 is a high performance ultra-low power stereo
DAC optimised for portable audio applications.
The device features stereo ground-referenced headphone
amplifiers using the Wolfson ‘Class-W’ amplifier techniques -
incorporating an innovative dual-mode charge pump
architecture - to optimise efficiency and power consumption
during playback. The ground-referenced headphone and line
outputs eliminate AC coupling capacitors, and both outputs
include common mode feedback paths to reject ground
noise.
Control sequences for audio path setup can be pre-loaded
and executed by an integrated control write sequencer to
reduce software driver development and minimise pops and
clicks via Wolfson’s SilentSwitch™ technology.
The analogue input stage can be configured for single
ended or differential inputs. Up to 3 stereo microphone or
line inputs may be connected. The input impedance is
constant with PGA gain setting.
A stereo digital microphone interface is provided, with a
choice of two inputs. The analogue or digital microphone
inputs can be mixed into the headphone or line output paths.
A dynamic range controller provides compression and level
control to support a wide range of portable recording
applications in conjunction with the digital microphone
interface. Anti-clip and quick release features offer good
performance in the presence of loud impulsive noises.
ReTuneTM Mobile 5-band parametric equaliser with fully
programmable coefficients is integrated for optimization of
speaker characteristics. Programmable dynamic range
control is also available for maximizing loudness, protecting
speakers from clipping and preventing premature shutdown
due to battery droop.
Common audio sampling frequencies are supported from a
wide range of external clocks, either directly or generated
via the FLL.
The WM8918 can operate directly from a single 1.8V
switched supply. For optimal power consumption, the digital
core can be operated from a 1.0V supply.
FEATURES
3.8mW quiescent power consumption for DAC to
headphone playback
DAC SNR 96dB typical, THD -86dB typical
2.4mW quiescent power consumption for analogue bypass
playback
Control write sequencer for pop minimised start-up and
shutdown
Single register write for default start-up sequence
Integrated FLL provides all necessary clocks
- Self-clocking modes allow processor to sleep
- All standard sample rates from 8kHz to 96kHz
Stereo digital microphone input
3 single ended inputs per stereo channel
1 fully differential mic / line input per stereo channel
Digital Dynamic Range Controller (compressor / limiter)
Digital sidetone mixing
Ground-referenced headphone driver
Ground-referenced line outputs
32-pin QFN package (4x4mm, 0.4mm pitch)
APPLICATIONS
Wireless headsets
Portable multimedia players
Handheld gaming
WOLFSON MICROELECTRONICS plc
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Production Data, January 2012, Rev 4.1
Copyright 2012 Wolfson Microelectronics plc



Wolfson Microelectronics WM8918
WM8918
BLOCK DIAGRAM
IN1L/DMICDAT1
IN2L
1µF
M
U PGA
X
DIGITAL MIC
INTERFACE
IN1R/DMICDAT2
IN2R
1µF
MICBIAS
MICVDD
M
U PGA
X
VMID
Reference
WM8918
DYNAMIC RANGE
CONTROLLER
(DRC)
5-BAND
EQUALISER
DIGITAL MONO
MIX
DIGITAL SIDE
TONE MIXING
DIGITAL VOLUME
CONTROL
CONTROL
INTERFACE
AUDIO
INTERFACE
TDM SUPPORT
DAC
DAC
FLL /
CLOCK
CIRCUITRY
M
U
HPOUTL
X
HPOUTFB
M
U
HPOUTR
X
CLASS-W GROUND-
REFERENCED OUTPUTS
M
U
LINEOUTL
X
LINEOUTFB
M
U
LINEOUTR
X
ADAPTIVE
CHARGE PUMP
CPVOUTN
CPVOUTP
2.2µF
Production Data
Ground-referenced
Class-W
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PD, Rev 4.1, January 2012
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Wolfson Microelectronics WM8918
Production Data
TABLE OF CONTENTS
WM8918
DESCRIPTION....................................................................................................... 1 
FEATURES ............................................................................................................ 1 
APPLICATIONS..................................................................................................... 1 
BLOCK DIAGRAM ................................................................................................ 2 
TABLE OF CONTENTS......................................................................................... 3 
AUDIO SIGNAL PATHS DIAGRAM ...................................................................... 6 
PIN CONFIGURATION .......................................................................................... 7 
ORDERING INFORMATION.................................................................................. 7 
PIN DESCRIPTION................................................................................................ 8 
ABSOLUTE MAXIMUM RATINGS ........................................................................ 9 
RECOMMENDED OPERATING CONDITIONS..................................................... 9 
ELECTRICAL CHARACTERISTICS ................................................................... 10 
TERMINOLOGY ............................................................................................................ 10 
COMMON TEST CONDITIONS .................................................................................... 10 
INPUT SIGNAL PATH ................................................................................................... 11 
OUTPUT SIGNAL PATH ............................................................................................... 11 
BYPASS PATH.............................................................................................................. 12 
CHARGE PUMP ............................................................................................................ 13 
FLL ................................................................................................................................ 13 
OTHER PARAMETERS ................................................................................................ 13 
POWER CONSUMPTION.................................................................................... 16 
COMMON TEST CONDITIONS .................................................................................... 16 
POWER CONSUMPTION MEASUREMENTS .............................................................. 16 
SIGNAL TIMING REQUIREMENTS .................................................................... 18 
COMMON TEST CONDITIONS .................................................................................... 18 
MASTER CLOCK .......................................................................................................... 18 
AUDIO INTERFACE TIMING ........................................................................................ 19 
MASTER MODE ............................................................................................................................................................ 19 
SLAVE MODE................................................................................................................................................................ 20 
TDM MODE ................................................................................................................................................................... 21 
CONTROL INTERFACE TIMING .................................................................................. 22 
DIGITAL FILTER CHARACTERISTICS .............................................................. 23 
DMIC FILTER RESPONSES......................................................................................... 24 
DMIC HIGH PASS FILTER RESPONSES .................................................................... 24 
DAC FILTER RESPONSES .......................................................................................... 25 
DE-EMPHASIS FILTER RESPONSES ......................................................................... 26 
DEVICE DESCRIPTION ...................................................................................... 27 
INTRODUCTION ........................................................................................................... 27 
ANALOGUE INPUT SIGNAL PATH .............................................................................. 28 
INPUT PGA ENABLE .................................................................................................................................................... 29 
INPUT PGA CONFIGURATION..................................................................................................................................... 29 
SINGLE-ENDED INPUT ................................................................................................................................................ 31 
DIFFERENTIAL LINE INPUT......................................................................................................................................... 31 
DIFFERENTIAL MICROPHONE INPUT ........................................................................................................................ 32 
INPUT PGA GAIN CONTROL ....................................................................................................................................... 32 
INPUT PGA COMMON MODE AMPLIFIER .................................................................................................................. 34 
ELECTRET CONDENSER MICROPHONE INTERFACE ............................................. 35 
MICBIAS CONTROL...................................................................................................................................................... 35 
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PD, Rev 4.1, January 2012
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